The present invention relates to a method for modulation and synchronous demodulation of color television signals processed according to the offset modulation and offset sampling principle and to an arrangement for implementing this method.
A method for compatibly increasing the detail resolution in a color television transmission by offset sampling with the aid of prior and subsequent planar filtering and full frame reproduction is described in an article by Broder Wendland entitled "Enlwicklungsalternativen fur zukunftige Fernsehsysteme" [Development Alternatives For Future Television Systems], published in "Fernseh- und Kinotechnik" [Television and Cinematic Art], Volume 34, No. 2, 1980. According to the method described in the cited publication, the desired signal information is transmitted over a limited bandwidth channel, with part of the signal information not being transmitted in its original spectral position but rather being placed into a carrier frequency position by the offset sampling. Further, the sampling frequency according to this method lies outside the bandwidth of the transmission channel. To reconstruct the signal information in its original spectral position, subsequent synchronous sampling is necessary at the receiving end.